Local Sound Field Synthesis by Virtual Secondary Sources

Sound field synthesis techniques like Wave Field Synthesis and Higher-Order Ambisonics aim at the physical synthesis of a desired sound field over an extended listening area. However, for practical setups the accuracy up to which the desired sound field can be synthesized over an extended area is limited. For certain applications it is desirable to limit the spatial extent of the listening area in order to increase the accuracy within this limited region for a given loudspeaker arrangement. Local sound field synthesis aims at a higher accuracy within a local listening area. An approach to local sound field synthesis is presented that is based on the concept of using virtual loudspeakers that are placed more densely around the local listening area than the existing loudspeakers. The approach is illustrated using Wave Field Synthesis as an example.